The rule is the same for all the files you're having difficulty with. Follow my instructions & you WILL be able to overcome your problems. If either of the 1st 2 options don't do the job to your pleasing, use your 'File Exchange control panel' & be careful to choose the specific applications of your choice for each file type. (Of course you can add file types & their variations.)

The other suggestion about a file utility such as Mac Army Knife allows you to set the creator of the file to the specific application of your choice. eg- Changing all jpgs you have to become Picture Viewer files will have the creator name of ogle. After changing, every time you double-click that file, it will automatically open with Picture Viewer. Or perhaps you'd prefer another app to open them. The principle is the same for all types of files. But don't muckaround with the file-type (unless it is incorrect & careful not to change to a file-type that is not equivalent) or use a program creator of the file when that program is not compatible with the file. Keep it simple! After all, all you want to do is have that file open with the type of app that would normally open it.

If you have tried all 4 options suggested but you're still not happy, report back to us in this thread (don't start a new thread!)